Porous surfaces of brick and stone building deteriorate over time because of many reasons, but a major cause of such deterioration are various deteriorating ingredients found in the air. There are many coating materials available for protecting these surfaces but, unfortunately, they wear out in time due to adverse weather conditions and other reasons. Usually, these coating materials have been applied by a brush or have been sprayed on under slight pressure. Shallow penetration of the surfaces of the porous materials by the protective coating material has thus resulted.
The apparatus of the present invention provides relatively deep penetration of the surface of the porous material by the protective liquid and accomplishes this with relatively simple and inexpensive equipment.
Moreover, when the protective liquid has superior heat insulating qualities, heat loss through the treated surface is substantially reduced. A suitable liquid containing a polyacrylic ester is PLEXI-SEAL, a trademark of Plexi-Seal Protective Corp., Long Island City, N.Y.